|11-15-2002 04:53 PM|
wd40 & vaseline. works great
[ November 15, 2002: Message edited by: 38 deluxe ]</p>
|11-15-2002 06:48 AM|
How did all this go from lubing the bores, skirts, and pins to "DRY"? I just happen to not oil the rings. I build all my engines that way and haven't had a ring related failure in over 20 years of engine building. If you're not comfortable with that then oil away. Like I said there's more than one way to do many things.
Just to explain my theory, whether it's right or wrong is open to discussion. Where does all that oil go that's trapped between the top ring, second ring and oil scraper? Especially if you're running a Total Seal or ZGS top ring. It really can't escape very quickly so it gets burned away during combustion. Burnt oil leaves a nasty residue, just look at the pistons out of any worn out engine that's burning oil. I build alot of engines with very low tension 2nd. rings, some are backcut to the point where the radial tension is almost non-existant. Many are of them are of the .043 thickness variety. Anyway the true sealing power of this type of ring comes from the matchup of the ring land and the bottom of the ring. This provides the seal that enables the pressure from behind the ring to force the ring outward. Any residue that remains on either surface will comprimise the seal. I actually flat lap the bottom of the rings then de-magnatize them. Of course the block is filled and plate honed and the finishes are obscene. Sounds kind of anal but is neccessary for rules-restricted classes like NHRA Stock Eliminator. I guess where I differ is that my business is race only so the volume isn't high.
|11-14-2002 06:52 PM|
|BOBCRMAN@aol.com||somebody is full of sh** when it comes to dry assembly, i worked in a heavy equipment shop and they hired a guy that for his first job assembled a large v-8 Perkins diesel tractor motor, he did this dry, i had never seen it done before and watched him quite closely, he pre lubed the motor before firing it with a pressure luber. this engine ran for 10 min then started to belch oil smoke, lost power and quit, the heads were removed and the cylinder walls looked like someone had run a rasp up and down them. needless to say the man was fired on the spot, and i had to tear down, rebore and re assemble the motor, so much for dry assembly, cost the owner over $5000.00 to repair.|
|11-14-2002 04:51 PM|
|email@example.com||The method I use seems to do fine. I blow the dust and grinder grit out with high pressure air, sand out the rust that has developed in the year since I had the cylinders bored, squirt whatever oil is in my drill press oil can at the time (usually Pep Boys 30W), shove teh slugs in with my nifty blue shim-steel ring compressor, bolt it all up and turn it on. ZOOM!!!|
|11-14-2002 04:32 PM|
|cranknrods||dry asembled engines?--hmmm i must pray to the car gods for others sins-however im sure those that sinned in this manner,soon after, offered their rings as a sacrafice.-i dont think the car gods are very happy about this!|
|11-14-2002 04:04 PM|
|woodz428||I'll throw mine in too. I used to oil ( amix of the oil to go in the engine and ATF) up until about 10 years ago and started using WD-40 instead, I've built hundreds of engines this way and have never had a failure. Whatever works for the guy building them , I guess, but dry....never.|
|11-14-2002 03:25 PM|
|4 Jaw Chuck||
You can assemble the rings on the pistons dry and then install them on a dry bore but...this should only be done on engines that have been bored and honed with a superfine finish like 600 or finer.
Why you ask.
The theory is this, on an engine the first few strokes up and down the bore before the engine starts is the break-in and compression in the cylinder will condense water in the air and form a lubricating film, actually this is how most oiless air compressors operate although they use carbon rings in this application. After the engine starts 90% of the break-in is already accomplished and oil slung off the crank will immediately lubricate the bore.
Should I do it?
Not unless you are intimate and confident that the engine was assembled perfectly and the bores are perfectly round (honed with torque plates) and the finish on the bores is very fine and absolutely clean.
Does 4 Jaw do it?
What are you nuts? Not on your life although I did this regularly on two stroke racing snowmobile and dirt bike engines (the oil is in the fuel!). I have seen instances where dry bores and dry rings have picked up and galled the bores after only a few minutes of running using this procedure especially with cast iron rings. Chrome-moly and straight chrome rings/bores are much more forgiving in this regard.
Why do people do it?
You got me, I think it is because they like to roll the dice and tempt the engine Gods because they think they are such great engine builders. Me, I like to appease them whenever I can and I say a little prayer whenever I start an engine for the first time. The engine can break-in slowly for all I care, it's a lot safer.
I use STP on every piston/ring because of the high pressure additives, it's good enough for an air cooled aircraft engine it's good enough for me. I do wipe off the excess mind you. Just because some guy says he does it how do you know he didn't at least give the rings a shot of WD-40 before he installed them. The BS can get thick at times.
Be careful out there.
|11-14-2002 02:38 PM|
|drewhelm||I've heard of people coating the cylinders with ATF. Actually, that's what I used on teh clyinder walls when I assembled the 455. Lightly oiled the rings, pins, and skirts, but the cylinder bores were prepped with ATF....Dexron III to be exact!!!|
|11-14-2002 02:37 PM|
|Airport Towing||Wow....Dry installing rings. Now I HAVE heard everything. Well I guess whatever turns you on is OK, but it sure sounds like a great way to ruin good parts to me. I personally have to scrub the block, just like engineguy said, but I'm kinda meticulous, so I do it at least twice. :-). I then follow engineczar's method almost to the letter, except I lubricate enough to make things slide just enough. I think the idea is to use just enough oil, but not too much. Yeah, engineczar is correct again, if there is more than a thin film of oil, it IS time for a rebuild. A thin film is all that's required for seal and lubrication. Sorry, but I actually know some NASCAR Engine builders (yeah I know, but it is TRUE) in North Carolina shops who would NEVER install piston rings dry. I know this because I have been present during assembly, so I would say whoever saiid that is WAY wrong. What exactly would be the point of dry installing rings anyways? Does anyone actually think or believe this would promote rapid break in or is it for some other reason? MY 2 cents. :-)|
|11-14-2002 02:17 PM|
|bullheimer||i think the light coating of oil would be okay if your so good you know the motor will start soon. i never am. with an old fashioned oil can i squirted a couple of shots into the plug hole and turned it by hand before i put the plugs in. you low/no oilers who are afraid of plug fouling might be interested to know it started on the first turn. but if you build mass amt's of engines you've built more in a week than i have in my life. since the rings dont move against the piston groove, it doesnt need lube right? if it aint broke, dont fix it. i sure as hell would not even think about putting them in dry as a bone, that sounds like insanity. but i'll bet the rings break in quicker that way!!|
|11-14-2002 01:46 PM|
Ok, let me set the record straight before I get anymore PM's/emails about this.
I never said I do the dry start thing. In fact, I have always done quite the opposite.
I brought this question up because after re-reading an engine article at project33.com, Sehr performance built his engine for him and stated that he builds all his engines this way. (Along with something about "this is the way NASCAR builders do it too...")
I never and will never try this method, like I said in my original post- I just fear the thought of dry metal to metal contact.
I suppose if people are doing it, it can be done, but I'm not willing to find out on my own.
I can see from the general response I recieved though, I am not the only one who thought this idea didn't sound too great. Call it old school, common sense, whatever you want - I just prefer there to be some kind of lubrication on moving parts.
Who knows, maybe we've been doing it all wrong for all these years. (Makes me wonder about priming the oil system before startup now... maybe thats not needed either. hehehe)
|11-14-2002 01:27 PM|
|Harlequin||I have always used a 50/50 mixture of 40# and stp…that has always worked fine for me…I am another addition to the club of hearing this for the first time…I think we need 4 JAW on this|
|11-14-2002 11:23 AM|
Add my name to the list. I have never heard of anyone installing pistons/ring with NO oil. My method is similar to czar's. First the engine is washed completely with HOT water and soap, then rinsed and blown dry using dry filtered air. Then the cylinders and all gasket sealing surfaces are wiped with clean lint-free cloth, using lacquer thinner or rubbing alcohol. Then, dried again this time with a fresh, dry, lint-free cloth. Cylinders are coated with 30# oil, then the rings, wrist pins and piston skirts are liberally oiled with 30#. Upper bearing shell is installed and lubed with ASSEMBLY lube (NOT moly lube or white (fishing reel) grease), then the piston/rod assembly is slid into the cylinder using a quality tapered ring installation tool, protection on the rod bolts. Crank is rotated so that the rod pin is at BDC before the piston is installed, that way you have room to work.
My engines are also built in a clean environment and always at a consistant temperature of 68 to 70 degrees.
Works for me.
|11-14-2002 11:04 AM|
|engineczar||This might be one of those questions where there is more than one way to skin a cat. Whatever way you learnt or were taught it is ok so long as the end result is what you want. I build 15-20 racing engines a year and I'm very comfortable with my methods and the results.|
|11-14-2002 10:49 AM|
|Quepas00||You should always lightly oil the rings and the skirt before installation.|
|This thread has more than 15 replies. Click here to review the whole thread.|